[PATCH v2 2/5] src/t_dir_offset2: Add an option to find file by name

Amir Goldstein
2021-04-25T07:14:52Z

Will be used to check for missing/stale entries.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
---
src/t_dir_offset2.c | 39 ++++++++++++++++++++++++++++++++++++++-
1 file changed, 38 insertions(+), 1 deletion(-)

diff --git a/src/t_dir_offset2.c b/src/t_dir_offset2.c
index 7aeb990e..7af24519 100644
--- a/src/t_dir_offset2.c
+++ b/src/t_dir_offset2.c
@@ -8,11 +8,13 @@
* that these offsets are seekable to entry with the right inode.
*/

+#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <stdint.h>
#include <stdlib.h>
+#include <string.h>
#include <sys/stat.h>
#include <sys/syscall.h>

@@ -32,7 +34,7 @@ static uint64_t d_ino_history[HISTORY_LEN];

void usage()
{
- fprintf(stderr, "usage: t_dir_offset2: [bufsize]\n");
+ fprintf(stderr, "usage: t_dir_offset2: [[bufsize] <filename> [-v]]\n");
exit(EXIT_FAILURE);
}

@@ -45,6 +47,9 @@ int main(int argc, char *argv[])
int bpos, total, i;
off_t lret;
int retval = EXIT_SUCCESS;
+ const char *filename = NULL;
+ int exists = 0, found = 0;
+ int verbose = 0;

if (argc > 2) {
bufsize = atoi(argv[2]);
@@ -52,6 +57,12 @@ int main(int argc, char *argv[])
usage();
if (bufsize > BUF_SIZE)
bufsize = BUF_SIZE;
+
+ if (argc > 3) {
+ filename = argv[3];
+ if (argc > 4 && !strcmp(argv[4], "-v"))
+ verbose = 1;
+ }
} else if (argc < 2) {
usage();
}
@@ -62,6 +73,14 @@ int main(int argc, char *argv[])
exit(EXIT_FAILURE);
}

+ if (filename) {
+ exists = !faccessat(fd, filename, F_OK, AT_SYMLINK_NOFOLLOW);
+ if (!exists && errno != ENOENT) {
+ perror("faccessat");
+ exit(EXIT_FAILURE);
+ }
+ }
+
total = 0;
for ( ; ; ) {
nread = syscall(SYS_getdents64, fd, buf, bufsize);
@@ -91,10 +110,28 @@ int main(int argc, char *argv[])
}
d_off_history[total] = d->d_off;
d_ino_history[total] = d->d_ino;
+ if (filename) {
+ if (verbose)
+ printf("entry #%d: %s (d_ino=%lld, d_off=%lld)\n",
+ i, d->d_name, (long long int)d->d_ino,
+ (long long int)d->d_off);
+ if (!strcmp(filename, d->d_name))
+ found = 1;
+ }
bpos += d->d_reclen;
}
}

+ if (filename) {
+ if (exists == found) {
+ printf("entry %s %sfound as expected\n", filename, found ? "" : "not ");
+ } else {
+ fprintf(stderr, "%s entry %s\n",
+ exists ? "missing" : "stale", filename);
+ exit(EXIT_FAILURE);
+ }
+ }
+
/* check if seek works correctly */
d = (struct linux_dirent64 *)buf;
for (i = total - 1; i >= 0; i--)
--
2.31.1